py/objfloat: Support raising a negative number to a fractional power.

This returns a complex number, following CPython behaviour.  For ports that
don't have complex numbers enabled this will raise a ValueError which gives
a fail-safe for scripts that were written assuming complex numbers exist.
crypto-aes
Damien George 5 years ago
parent 62849b7010
commit bdc6e86e07
  1. 7
      py/objfloat.c
  2. 4
      tests/float/complex1.py

@ -298,6 +298,13 @@ mp_obj_t mp_obj_float_binary_op(mp_binary_op_t op, mp_float_t lhs_val, mp_obj_t
if (lhs_val == 0 && rhs_val < 0) {
goto zero_division_error;
}
if (lhs_val < 0 && rhs_val != MICROPY_FLOAT_C_FUN(floor)(rhs_val)) {
#if MICROPY_PY_BUILTINS_COMPLEX
return mp_obj_complex_binary_op(MP_BINARY_OP_POWER, lhs_val, 0, rhs_in);
#else
mp_raise_ValueError("complex values not supported");
#endif
}
lhs_val = MICROPY_FLOAT_C_FUN(pow)(lhs_val, rhs_val);
break;
case MP_BINARY_OP_DIVMOD: {

@ -53,6 +53,10 @@ print(type(hash(1j)))
# float on lhs should delegate to complex
print(1.2 + 3j)
# negative base and fractional power should create a complex
ans = (-1) ** 2.3; print("%.5g %.5g" % (ans.real, ans.imag))
ans = (-1.2) ** -3.4; print("%.5g %.5g" % (ans.real, ans.imag))
# check printing of inf/nan
print(float('nan') * 1j)
print(float('inf') * (1 + 1j))

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